PROGRAM d8r11(input,output);
(* driver for routine ECLAZZ *)
CONST
   n=15;
TYPE
   glnarray = ARRAY [1..n] OF integer;
VAR
   i,j,k,lclas,nclass : integer;
   nf,nflag,nsav : glnarray;

FUNCTION equiv(i,j: integer): boolean;
BEGIN
   equiv := FALSE;
   IF ((i MOD 4) = (j MOD 4)) THEN  equiv := TRUE
END;

(*$I MODFILE.PAS *)
(*$I ECLAZZ.PAS *)

BEGIN
   eclazz(nf,n);
   FOR i := 1 to n DO BEGIN
      nflag[i] := 1
   END;
   writeln;
   writeln('Numbers from 1-15 divided according to');
   writeln('their value modulo 4:');
   lclas := 0;
   FOR i := 1 to n DO BEGIN
      nclass := nf[i];
      IF (nflag[nclass] <> 0)  THEN BEGIN
         nflag[nclass] := 0;
         lclas := lclas+1;
         k := 0;
         FOR j := i to n DO BEGIN
            IF (nf[j] = nf[i]) THEN BEGIN
               k := k+1;
               nsav[k] := j
            END
         END;
         write('Class',lclas:2,':   ');
         FOR j := 1 to k DO write(nsav[j]:3);
         writeln
      END
   END
END.